On 11/23/2016 11:33 AM, Dawid Zamirski wrote:
> On Wed, 2016-11-23 at 11:00 -0500, Dawid Zamirski wrote:
>> On Wed, 2016-11-23 at 08:55 -0500, John Ferlan wrote:
>>> [...]
>>>> +
>>>> +static vboxDriverPtr
>>>> +vboxGetDriverConnection(void)
>>>> +{
>>>> + virMutexLock(&vbox_driver_lock);
>>>> +
>>>> + if (vbox_driver) {
>>>> + virObjectRef(vbox_driver);
>>>> + } else {
>>>> + vbox_driver = vboxDriverObjNew();
>>>> +
>>>> + if (!vbox_driver) {
>>>> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>>>> + _("Failed to create vbox driver
>>>> object."));
>>>> + return NULL;
>>>> + }
>>>> + }
>>>> +
>>>> + if (vboxSdkInitialize() < 0 || vboxExtractVersion() < 0) {
>>>
>>> In this path should vboxSdkUninitialize be called (since it
>>> wouldn't
>>> be
>>> called in the destroy path)?
>>
>> If vboxSdkUnintialize fails, VBoxSVC is not started so it does not
>> need
>> to be unintialized - which is in line with the sample code included
>> SDK
>> where it returns with EXIT_FAILUE in main if pfnClientInifialize
>> fails.
>> However, if vboxExtractVersion fails (unlikely) we might want to call
>> gVBoxAPI.UPFN.Unintialize(vbox_driver) directly (not via
>> vboxSdkUninitialize as it checks connectionCount > 0 which on failure
>> would be 0). I've just tested both cases with
>> gVBoxAPI.UPFN.Unintialize
>> in the failure path, and calling it does not do any harm in both
>> cases,
>> so I guess it would be a good idea to put it there.
>>
>
> Actually, I was wrong in that it's safe to call
> gVBoxAPI.UPFN.Unintialize when vboxSdkInitialize fails - I got segfault
> when attempting to connect twice in VBOX_RELEASE(data->vboxObject).
> It's safe to do this though:
>
> if (vboxSdkInitialize() < 0) {
> virObjectUnref(vbox_driver);
> virMutexUnlock(&vbox_driver_lock);
>
> return NULL;
> }
>
> if (vboxExtractVersion() < 0) {
> gVBoxAPI.UPFN.Uninitialize(vbox_driver);
> virObjectUnref(vbox_driver);
> virMutexUnlock(&vbox_driver_lock);
>
> return NULL;
> }
>
> i.e do not uninitalize on initialize failure, but do unintialize on
> vboxExractVersion failure.
>
Fair enough - what about the 4 places in vboxSdkInitialize that return
failure after gVBoxAPI.UPFN.Initialize is successful?
John
FWIW: A closer look at vboxExtractVersion made me realize the "normal"
fall through code path goes through the 'failed:' label, which looks odd.
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